Telephone-repeater



(No Model.) 3 SheetsS11eet-1.

D. E. SMITH.

TELEPHONE REPEATER. No. 297,724. Patented Apr. 29, 1884,

(No Model) I 3 Sheets-Sheet 3. D. E. SMITH.

TELEPHONE REPEATEB.

No. 297,724. Patented Apr. 29, 1884.

I .Jv'mamw 04 v #6. 5

Ill-m: De '0@ N. PETERS. Phulo-ljlhcgraplur. Waxhingtnm DC.

. UNITE STATES ATIENT. OFFICE.

DANIEL E.' SMITH, OF HARTFORD, CONNECTICUT.

T ELEPHONE-REPEATER SPECIFICATION forming part of Letters Patent No. 297,724, dated April 29, 1884. I

h Application filed September 27. 1883. (No model.)

To all whom it may concern..-

Be it known that I, DANIEL E; SMITH, of Hartford, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Telephone-Repeaters; and I do hereby declare that the following is a full, clear, and exact description thereof, whereby a person skilled in the art can make and use the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon.

Like lettersin the figures indicate the same parts.

Figure 1 is a sideview of the inductioncoils and transmitters used in my improved device, mounted upon a frame and compactly arranged for convenience in use. Fig.2 is a top view of same. Fig. 3 is an end view of same. Fig. A is a diagram view of the various parts of my device, showing the method of connection. Fig. 5 is a diagram view of the various parts of my device, showing a receiving-telephone in place of the rheostat.

My inventionrelatcs to the class of devices adapted to convey from one lengthof line electricalwaves or impulses generated in that line, as by means of the telephone and its ordinary accessories, to another line.

My improvement is especially applicable to telephone-lines, in which, as at present used, serious trouble is 'caused'by induced currents. These induced currents in telephone-lines are, other things beingequal, proportioned to the length of the line between the extreme stations. By means of my invention I greatly reduce these induced currents.

In the accompanying drawings, the letter a denotes the frame or stand, of ordinary insulating material, as wood; I), a repeating-magnet; 0, a helix arranged about the end of this induction-coil joins up to the rheostat, and the other, f, connects with the main wire A, to a point beyond the repeating-station. The line from this point (New Haven) to the repeating-station connects with the helix of the duplicate magnet b at this station and then I transmitter through the primary circuit of the induction-coil, amplified in. the secondary circuit of the coil, and pass through to the main line to the farther station, the rheostat interposed between the induction-coils on this secondary circuit being of a sufficient resistance to more than counterbalance the resistance of the wires on either side of the repeatingstation, and the main part of the waves, therefore, following the path of the least resistance, are repeated in thetelephone at New Haven, the farther. station. The use of this interposed resistance is to prevent a great portion of the currents from one station from passing over the line to the farther station without passing through the coil 12 or 1;. Whatever current is generated at the transmitter at one station is thus made effective at the repeatingmagnet, and the great resistance of the secondarie's of the two induction-coils, together with the extra resistance R, will divert the greater part of such current into the desired channel-viz., through the repeating-magnets b orb.

\ In the place of the rheostat in the secondary circuit of the induction-coils, I may use'a receiving-telephone so arranged as to switch into the circuit, thus enabling me to use the telephone as an intermediate, although imperfeet, receiver. Myimprovement in this regard is a complete telephone-relay. The overly- IOO circuits, the said repeating-magnets in 0perative proximity to microphones in local-battery circuits, each battery-circuit including the primary of an induction-coil, the secondaries of the two induction-coils connected in series and with the line beyond the repeating-magnets, and the resistance included in said secondary circuit, all'substantially as described.

DANIEL E. SMITH.

\Vitnesses:

Orms. L. BURDETT, ALBERT (J. TANNER. 

